The invention relates to an in-line roller skate and specifically to an in-line roller skate for use by children that selectively provides enhanced lateral stability and user control of the direction of movement of the skate. The skate has a roller assembly configurable between a normal mode in which both halves of the roller are abutting and a stable mode in which the halves are spaced apart to enhance the lateral stability of the skate. The skate also as a roller assembly that is configurable to either a free wheeling, a forward only, or a full stop configuration, therefore limiting the direction of movement of the skate.
Roller skates typically consist of a boot portion attached to a sole portion supported by a set of rollers. Conventional four wheel roller skates have a pair of front rollers sharing one axis of rotation and a pair of rear rollers sharing a second axis of rotation that is parallel to the axis of rotation of the front rollers. Since the rollers of each pair are transversely displaced from the longitudinal center-line of the roller skate, the conventional roller skate inherently provides substantial lateral stability.
In contrast, in-line roller skates typically have from three to six rollers arranged in longitudinal alignment along the longitudinal center-line of the skate. Each roller has an unique axis of rotation that is parallel to the axes of rotation of the other rollers. Since none of the rollers are transversely displaced from the longitudinal center-line of the skate, the in-line skate provides very little inherent lateral stability.
Roller skating on in-line skates, which simulates the fed and motion of skating on ice while using a conventional ice skate, has become quite popular. However as discussed, since the in-line skate has a row of longitudinally aligned rollers, it does not have the inherent stability of a conventional four wheel roller skate. Consequently many people, especially children, have difficulty keeping their balance while using in-line roller skates. Furthermore, ice skating normally takes place on a substantially planar surface while roller skating takes place on land, which may include hills having a wide range of gradients thus making mastery of the in-line roller skate even more difficult.
One proposed method of creating additional lateral stability in an in-line skate is to place a roller in a position that is transversely displaced from the longitudinal center-line of the skate. This can be accomplished by moving an existing roller or adding an additional roller at the desired location. Although this method does provide enhanced stability should the skate tilt towards the transversely displace roller, no additional stability is provided should the skate tilt away from the roller. Hence, this method provides enhanced lateral stability in only one direction with respect to the longitudinal center-line of the skate.
Several such in-line roller skates have been proposed that provide added lateral stability to the skate. U.S. Pat. No. 5,295,701 to Reiber et al. discloses an in-line skate having a center roller that is alternatively positionable in a longitudinally aligned position relative to the front and rear rollers or a transversely displaced position relative to the other rollers. Hence, the lateral stability of the skate is increased by moving the center roller out of alignment with respect to the other rollers. As discussed above however, the stability of the skate is enhanced only in the direction in which the center roller is displaced.
U.S. Pat. No. 5,183,276 to Pratt discloses an in-line skate having a removable training roller. The roller is housed in a U-shaped training bracket so that the training roller has an axis of rotation that is parallel with the axis of rotation of the other rollers and transversely displaced from the longitudinal center-line of the skate. The training roller engages the travel surface when the skate engages the travel surface at an acute angle. Therefore, the design provides for increased stability only when the skate is tilted towards the travel surface in the direction of the training roller such as when making a sharp turn. Furthermore, this device requires significant assembly and disassembly to convert between the normal in-line skate and training skate configurations.
The skate disclosed in U.S. Pat. No. 3,901,520 to McMahan, is configurable as a two wheel in-line skate or a four wheel conventional roller skate. To convert from an in-line to a conventional skate, the operator removes roller 17 from between channel walls 16 and installs two rollers 17, one positioned on the outside of each channel wall 16 as shown in FIG. 4. Reconfiguring the skate requires the removal of the entire roller assembly and thus requires more time and effort than most children are willing to expend.
U.S. Pat. No. 87,225 to Topliff and Ely discloses a bicycle having two rear wheels that can be positioned apart from each other for increased stability, or together constituting a single rear wheel. Configuration of the wheel is accomplished by rotating a V-shaped rear axle. When the axle's middle is higher than its ends, the rear wheels will move toward the middle of the axle to act as a single wheel. When the axle is rotated so that its ends are higher than the middle, the wheels will slide along the axle toward the ends to provide the greater stability of a tricycle. As can be seen in FIG. 2, this system works best when each half of the axle is substantially longer than the thickness of the wheel. This design is not readily adaptable to a roller skate because the small diameter of the roller would make the change in height of the roller skate noticeable to the user.
Another desirable feature of an in-line skate adapted for use with children or inexperienced adults is to incorporate a movement limiting device. By limiting the rotation of one or more rollers to one rotative direction (corresponding to forward movement of the skate), the frictional forces provided by the skate, should the skate be urged in the backward direction, would allow the user to generate the desired propulsion by pushing straight back on the skate (rather than having to angle the skate to the side). In addition, this configuration allows the user to skate up a sloping travel surface without the fear of inadvertently rolling backwards down the slope. Furthermore, by configuring the skate so that one or more rollers cannot rotate in either direction prevents movement of the skate in either the forward or backward direction. In this configuration, the user can "walk" in the skates to get more comfortable with wearing and keeping his balance in the skates.
Unlike a conventional roller skate, the movement limiting mechanism in an in-line skate should be laterally compact so that exposed components do not reduce the aesthetics of the skate. More importantly, a laterally compact design reduces exposure of the components, thus reducing the vulnerability and increasing the reliability of the mechanism.
With regard to controlling the rotational motion of skate wheels, U.S. Pat. No. 4,932,676 to Klamer discloses a design for a conventional roller skate that is configurable between a free wheeling, forward only, or full stop configuration. A pair of rollers have gear-like teeth 80 on the inside cylindrical surfaces of the rollers. Camming member 130 positions pawl 100 to selectively engage teeth 80 and therefore control the movement of the rollers. Since the pawl extends across the body of the skate to engage both rollers, and the camming member engages the pawl intermediate the rollers, this design is not well suited for use in an in-line skate.
Another known design for wheel motion control in an in-line skate is to mount a knurled rod for selective engagement with the outside rolling surface of one of the wheels. The rod can be manually moved between a position in which the rod locks the wheel against rearward rotation while permitting forward rotation, and a position in which the rod does not engage the wheel. This design does not provide for engagement of the wheel to prevent rotation in both directions.